Adjustable shelves are commonly associated with both the freezer compartment and the fresh food compartment of conventional refrigerators. When the shelves are constructed as sliding shelves, opposite generally parallel sides of the shelves rest upon and slide relative to horizontally aligned ribs or grooves formed in opposing pairs in side walls or inner liners of the compartments. Other such shelves slide relative to shelf brackets which have hooks hooked into slots of vertical tracks mounted in the refrigerator compartments. Typical sliding shelves are exemplified by the disclosures of U.S. Pat. Nos. 6,422,673 B1 and 5,362,145 issued respectively on Jul. 23, 2002 and Nov. 8, 1994. In each case the shelves in their most simplistic construction are defined by a piece of tempered glass bordered by a rim or border which is either snap-secured or injection molded to the tempered glass.
It is also conventional to utilize vertically adjustable shelves in refrigerators which, instead of a tempered glass panel, utilize a supporting surface defined by crossing wires. Wire shelves typical of the latter construction are disclosed in U.S. Pat. No. 5,004,302 granted on Apr. 2, 1991. Two groups of wires are normal to each other and are welded or otherwise secured to cantilevered brackets which can be vertically adjusted within compartments of a refrigerator.
Other conventional shelves are injected molded as a single piece of material, as disclosed in U.S. Pat. No. 5,188,246, and have a hook for cantilevered support from a slat wall typically used in stores and supermarkets. Hollow ribs reduce the weight of the shelf while providing requisite rigidity for supporting articles/products thereupon.
U.S. Pat. No. 3,446,371 granted on May 27, 1969 describes the manufacture of “wire racks” by “laying many wires across two edge members and then welding the wires to the edge members. The exposed cut ends of the wires must be finished to eliminate the dangerous sharp edge. After the finishing operation, some racks are dipped in plastic for decorative and protective purposes, while others are protected by chrome plating.” The disadvantages of such racks include the cut ends which create dangerous sharp edges and welding which is “an expensive step in the manufacture of present racks.” This patent avoids the latter disadvantages by encasing each wire in a plastic coating, inserting the ends of each wire through slots into a metal shell and filling the shells with a plastic filling which fills the shells and forms a homogeneous bond with the plastic coated wires. Alternatively, the side shells are not utilized but instead plastic coated wires are placed atop opposite parallel metal bars and the latter are encapsulated by plastic introduced into molds which cures and is bonded to the plastic of the wires.